History
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General view of the Ascó I and II nuclear power plant, Tarragona.
Nuclear energy was not the discovery of just one person; it was the result of decades of scientific research. From the discovery of radioactivity in 1896 to nuclear fission in 1938, various breakthroughs made it possible to understand the structure of the atom and the enormous energy that can be released in nuclear processes.
Who took the first steps to discover nuclear energy?
The first step was taken by the French physicist Henri Becquerel in 1896.
While studying uranium salts, he observed that they emitted radiation spontaneously, without the need for an external energy source.
This discovery was accidental: Becquerel left the salts on a photographic plate in a dark drawer and, when developing it, found that the uranium had “imprinted” itself. This phenomenon, known as radioactivity, marked the beginning of the study of nuclear energy.
While scientists like Rutherford advanced the understanding of the atom’s structure and the Curies studied radioactivity, it was Otto Hahn and Fritz Strassmann who obtained the first experimental results in 1938.
At the end of that same year, Lise Meitner and Otto Frisch provided the first theoretical explanation of nuclear fission, calculating the energy released. Their work helped better understand the atom and the origin of that energy.
We explain each discovery step by step.
Control room of the Ascó nuclear power plant.
What did Marie and Pierre Curie contribute to nuclear energy?
Following Becquerel's discovery, Marie and Pierre Curie delved deeper into the study of radioactivity.
They analysed different materials and succeeded in isolating new radioactive elements, such as polonium and radium. In doing so, they confirmed that radioactivity is a property inherent to certain atoms and not the result of a common chemical reaction.
Their research helped demonstrate that some atoms could emit energy spontaneously and that this released energy did not come from chemical reactions, but from within the atom itself.
For this work, Marie Curie became the first person to receive two Nobel Prizes in different categories, Physics and Chemistry, contributing to the development of nuclear physics as a scientific field.
What discovery allowed us to understand nuclear energy?
The first major step in understanding nuclear energy was the discovery of radioactivity in 1896 mentioned earlier. Henri Becquerel proved that certain substances, such as uranium salts, spontaneously emitted radiation capable of leaving a mark on photographic plates, even without light.
What does this mean? The energy did not come from the outside, but from inside the atom.
From that point on, science began to understand that phenomena capable of releasing energy occurred inside the atom, and especially in its nucleus.
This knowledge did not emerge all at once, but over several decades of research into atomic structure and radioactivity.
In 1905, Albert Einstein formulated the equation E = mc2 . It did not yet describe nuclear fission, but it did present a key idea: mass and energy are equivalent, and a small amount of matter can be transformed into a huge amount of energy.
What role did the study of the atom play in nuclear energy?
To advance this knowledge, it was necessary to understand what an atom is like on the inside. At the beginning of the 20th century, Ernest Rutherford demonstrated that most of an atom's mass is concentrated in a central nucleus, surrounded by electrons.
However, a key piece was missing to better understand that nucleus. In 1932, James Chadwick discovered the neutron, a particle in the atomic nucleus with no electrical charge.
This finding was fundamental: because it has no charge, the neutron could be used as a "bullet" to penetrate other nuclei without being repelled, opening the door to the experiments that, years later, would lead to the discovery of nuclear fission.
When was nuclear fission discovered and why was it key?
The answer came in 1938, when Otto Hahn and Fritz Strassmann discovered that the uranium nucleus could split into smaller parts when bombarded with neutrons. Shortly thereafter, this phenomenon became known as nuclear fission.
Moreover, this process can trigger a chain reaction, in which the released neutrons cause further fissions, multiplying the energy generated.
When, where, and how did nuclear energy begin to be used?
Once nuclear fission was understood in 1938, the next challenge was to prove that a chain reaction could be triggered and controlled. In 1942, a team led by the Italian-American physicist Enrico Fermi achieved this.
Fermi had discovered that by using slow (moderated) neutrons, he could induce fissions more efficiently, which led him to design an experimental reactor known as an “atomic pile”.
On 2 December 1942, on a court at the University of Chicago, Fermi succeeded in initiating the world's first self-sustaining and controlled nuclear chain reaction. This experiment confirmed that it was possible to release and control the energy from the atomic nucleus safely, marking the birth of the controlled nuclear era.
This milestone paved the way for the peaceful use of nuclear energy, linking the scientific discovery of fission to its first practical application a few years later.
A key milestone came in 1951, in Idaho (United States), when an experimental reactor produced electricity from nuclear energy for the first time.
Shortly thereafter, in 1954, the then Soviet Union inaugurated the first nuclear power plant connected to an electrical grid in Obninsk, marking the beginning of the commercial use of this energy.
Since then, nuclear energy has spread across the world, primarily for the continuous, large-scale generation of electricity.
In Spain, the first nuclear power plant to go into operation was José Cabrera (Guadalajara), which was connected to the grid in 1968. Known as Zorita, it remained operational until 2006.
Who discovered nuclear energy?
Key scientists and dates
Discovering nuclear energy was the result of the work of many people over time.
1896
Henri Becquerel
Discovers radioactivity.
1898
Marie and Pierre Curie
Isolate new radioactive elements.
1905
Albert Einstein
Explains the relationship between mass and energy.
1932
James Chadwick
Discovers the neutron.
1938
Lise Meitner and Otto Frisch
Explain nuclear fission based on the experiments of Hahn and Strassmann.
1942
Enrico Fermi
Achieves the first sustained and controlled nuclear chain reaction.
1951
Electricity is generated from nuclear energy in a controlled manner for the first time.
In summary:
- 1896: Henri Becquerel discovers radioactivity.
- 1898: Marie and Pierre Curie isolate new radioactive elements.
- 1905: Albert Einstein explains the relationship between mass and energy.
- 1932: James Chadwick discovers the neutron.
- 1938: Lise Meitner and Otto Frisch explain nuclear fission based on the experiments of Hahn and Strassmann.
- 1942: Enrico Fermi achieves the first sustained and controlled nuclear chain reaction.
- 1951: electricity is generated from nuclear energy in a controlled manner for the first time.
The discovery of nuclear energy is not the achievement of a single person. It is the result of the collective work of many scientists. Each discovery has made it possible to advance our understanding of the processes that occur inside the atom.
Today, nuclear energy remains a key part of energy development and continues to play an essential role in electricity generation and medical applications, showing how science, driven by curiosity and collaboration, continues to transform the world.
FAQ
It was not a single person; it was the result of various scientific discoveries over time.
The discovery of radioactivity in 1896 by Henri Becquerel.
In 1938, with the discovery of nuclear fission.
Yes, primarily for electricity generation and medical applications.
